Mechanical exfoliation apparatus

ABSTRACT

Apparatus to deliver predetermined forces, containers to hold particulate material and media, media, and the associated parameters for operating such equipment along with methods and compositions provided by the apparatus and methods.

This application is a divisional application from U.S. patentapplication Ser. No. 14/931,236, filed Nov. 3, 2015, currently pending,which is a divisional application of Ser. No. 13/435,260, filed Mar. 30,2012, currently pending, from which priority is claimed.

BACKGROUND OF THE INVENTION

There are several inventions and efforts to produce graphene chemically,thermally, and mechanically. Exfoliation involves the removal of thelayers on the graphite's outermost surface. Ball milling is the mostused of these methods, and this method involves milling the graphene ina closed container using various milling media. The ball mill moves inonly one direction, that is, rotational on a horizontal axis. Prior artmethods have described the results, however, they have failed todescribe the specific mechanical forces in type and size, and the systemof components required for success.

The applicant is aware of WO2011006814 that deals with a wet process forproviding particulate materials.

BRIEF DESCRIPTION OF THE INVENTION

The instant invention, in one embodiment, deals with an apparatus thatincludes a system of components to mechanically exfoliate particulatematerials using a multi-axis approach. In this embodiment, layers ofparticulate material or multilayer material are removed via a controlledshear by using a mechanical movement.

The apparatus of this invention includes a machine to deliver forces,containers to hold particulate material and media, the media, and theassociated parameters for operating such equipment along with methodsand compositions provided by the apparatus and methods.

Thus, what is claimed in one embodiment, is an apparatus formechanically exfoliating particulate material with a basil plane, saidapparatus comprising in combination a support frame, a motor mount, amotor mounted on the motor mount, the motor having a drive shaft,wherein the drive shaft has a driven flywheel mounted on it.

The support frame has a non-stationary plate surmounted on it by mountedshock absorbers. The non-stationary plate has a front end and a backend, and it has a non-stationary plate rigidly surmounted on it.

There is a processor assembly comprising a main drive shaft having twoends extending through drive shaft mounts, the main drive shaftcomprising a flywheel between the ends of the main drive shaft.

There is one or more cams on the main drive shaft, and a fastening meanson each end of the main drive shaft to maintain the main drive shaft inthe drive shaft mounts.

There is a canister carrier mounted on each cam, the canister carriercomprising a hub, wherein the hub has an external surface mounted cradleand an internal flat surface supporting bearings.

There is a stabilizer drive mechanism, the stabilizer drive mechanismcomprising a ring gear driven by a pinion gear, a secondary drive shaftsurmounted on the non-stationary flat plate. The secondary drive shaftis mounted in secondary drive shaft mounts and surmounted on thenon-stationary flat plate.

The secondary drive shaft has at least three first drive wheels. Thereis a drive link connecting each first drive wheel with an aligned seconddrive wheel.

In addition there is an embodiment which is an apparatus formechanically exfoliating particulate material, the apparatus comprisingin combination a support frame. The support frame is comprised of anupper bar frame and a lower bar frame, wherein the upper bar frame andlower bar frame are supported by vertical legs. The upper bar frame andlower bar frame are parallel and spaced apart from each other.

There is a motor mount mounted on and supported by the lower bar frameand there is a motor mounted on said motor mount, the motor having adrive shaft and the drive shaft having a driven flywheel mounted on it.

The upper bar frame has a non-stationary plate surmounted thereon by atleast four corner mounted shock absorbing mounts. The non-stationaryplate has a front end and a back end. The non-stationary plate hasrigidly surmounted on it, drive shaft mounts. The non-stationary platehas two large openings on either side of a smaller centered opening andthe drive shaft mounts are located on the outside edges of the largeopenings.

There is a processor assembly compiling: a main drive shaft having twoends extending through ail drive shaft mounts. The main drive shaftcomprises a flywheel centered between the ends of the main drive shaft.There are two cams, each centered between the flywheel and an end of themain drive shaft, and a fastening means on each end of the main driveshaft to maintain the main drive shaft in the drive shaft mounts.

There is a canister carrier mounted on each cam, the canister carriercomprising: a hub, wherein the hub has an external surface mountedcradle and an internal flat surface supporting bearings, there beingmounted on an outside hub, a drive component, such as a stabilizer ringgear. There is rotatably mounted on the main drive shaft, adjacent tothe stabilizer ring gear, a stabilizer housing, the stabilizer housingcontaining internal bearings adjacent to the main drive shaft, whereinthere is a stabilizer pinion gear surrounding the stabilizer housing andmeshing with the stabilizer ring gear.

There is a stabilizer drive mechanism, the stabilizer drive mechanismcomprising a secondary drive shaft surmounted on the non-stationary flatplate near the backend. The secondary drive shaft is mounted insecondary drive shaft mounts, surmounted on the non-stationary flatplate. The secondary drive shaft has at least three first drive wheels,one each near an end of the secondary drive shaft and one centered onthe secondary drive shaft.

The main drive shaft has at least three second drive wheels, each beingaligned with second end first drive wheels on the secondary drive shaft,the centered first drive wheel being aligned with a third drive wheelmounted on a gear reducer. The gear reducer is surmounted on thenon-stationary flat plate between the flywheel and the secondary shaft.The gear reducer has a fourth drive wheel mechanically connected to athird drive wheel by reducing gears, the fourth drive wheel and centeredfirst drive wheel are connected by a drive link, the drive linkconnecting each of the first drive wheel with an aligned second drivewheel.

In another embodiment, there is an apparatus for mechanicallyexfoliating particulate material, the apparatus comprising incombination: a support frame. The support frame is comprised of an upperbar frame and a lower bar frame, wherein the upper bar frame and lowerbar frame are supported by vertical legs. The upper bar frame and lowerbar frame are parallel and spaced apart from each other.

There is a motor mount mounted on and supported by the lower bar frameand there is a motor mounted on said motor mount, the motor having adrive shaft and the drive shaft having a driven flywheel mounted on it.

The upper bar frame has a non-stationary plate surmounted thereon by atleast four corner mounted shock absorbing mounts. The non-stationaryplate has a front end and a back end. The non-stationary plate hasrigidly surmounted on it, drive shaft mounts. The non-stationary platehas two large openings on either side of a smaller centered opening andthe drive shaft mounts are located on outside edges of the largeopenings.

There is a processor assembly comprising: a main drive shaft having twoends extending through all drive shaft mounts. The main drive shaftcomprises a flywheel centered between the ends of the main drive shaft.There are two cams, each centered between the flywheel and an end of themain drive shaft, and a fastening means on each end of the main driveshaft to maintain the main drive shaft in the drive shaft mounts.

There is a canister carrier mounted on each cam, the canister carriercomprising: a hub, wherein the hub has an external surface mountedcradle and an internal flat surface supporting bearings, there beingmounted on an outside hub, a stabilizer ring gear. There is rotatablymounted on the main drive shaft, adjacent to the first stabilizer wheel,a stabilizer housing, the stabilizer housing containing internalbearings adjacent to the main drive shaft, wherein there is a secondstabilizer wheel surrounding the stabilizer housing and meshing with thefirst stabilizer wheel.

There is a stabilizer drive mechanism, the stabilizer drive mechanismcomprising a secondary drive shaft surmounted on the non-stationary flatplate near the backend. The secondary drive shaft is mounted insecondary drive shaft mounts, surmounted on the non-stationary fiatplate, The secondary drive shaft has at least three first drive wheels,one each near an end of the secondary drive shaft and one centered onthe secondary drive shaft.

The main drive shaft has at least three second drive wheels, each beingaligned with second end first drive wheels on the secondary drive shaft,the centered first drive wheel being aligned with a third drive wheelmounted on a gear reducer. The gear reducer is surmounted on thenon-stationary flat plate between the flywheel and the secondary shaft.The gear reducer has a fourth drive wheel mechanically connected to athird drive wheel by reducing gears, the fourth drive wheel and centeredfirst drive wheel are connected by a drive link, the drive linkconnecting each of the first drive wheel with an aligned second drivewheel.

In yet another embodiment, there is a drive shaft. The drive shaft isintegral and comprises a linear shaft having two terminal ends and acenter point. The linear shaft has fixedly mounted at the center point,a flywheel. There are two cams, each cam having a near end and a distalend. Each cam has an opening through it whereby the opening begins atthe near end near a bottom edge of the cam, and terminates through thedistal end near a top edge. The linear shaft extends through the openingin the cam and extends beyond the distal end of the cam. The drive shafthas mounted on it, a wheel drive adjacent to the flywheel.

In still another embodiment of this invention there is a ring gear. Thering gear comprises: an inside surface and an outside surface, theinward surface is comprised of a plurality of gear teeth, the number andshape of gear teeth being matched to mesh with a corresponding gear onan adjacent pinion gear.

A further embodiment is a cam assembly comprising a cylindrical housing.The cylindrical housing has a near end and a distal end and an openingextending from the near end through the distal end. The opening beginsat the near end of the cam and near a bottom edge and terminates throughthe distal end near a top edge, the distal end having an off round, atleast one said end cap having a valve inserted therein

Yet another embodiment is a carrier assembly for canisters. The carrierassembly comprises a hubbed housing having an open center through ifwith an internal surface. The hub has at least two bearings mounted onthe internal surface of the housing and internal to each hub. The hubssupport an integral canister cradle attached to the hubs. One hub has astabilizer ring gear fixedly attached thereto such that the gear face ofthe gear faces away from the hub.

In yet another embodiment, there is in combination a carrier assemblyand at least one canister.

is a canister embodiment, the canister comprising: a hollow cylinderhaving two terminal ends, each of the terminal ends having a sealablecap mounted thereon. There is at least one end cap having a valveinserted therein.

SUMMARY DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view in perspective of the apparatus of this invention.

FIG. 2 is a full top view of the apparatus of this invention.

FIG. 3 is a full front view of the apparatus of this invention.

FIG. 4 is a full end view of the apparatus of this invention from theend opposite the motor.

FIG. 5 is a full end view of the apparatus of this invention from themotor mount end.

FIG. 6 is a full side view of a main drive shaft of this invention withits component parts.

FIG. 7 is a view in perspective of the main drive shaft of FIG. 6.

FIG. 8 is a full side view of a cam of this invention.

FIG. 9 is a full end view of a cam of this invention showing therectangular inset and opening therethrough.

FIG. 10 is a view in perspective of the cam of FIG. 8.

FIG. 11 is a cross sectional view of the cam of FIG. 9, through lineA-A.

FIG. 12 is a partial cross section of the canister carrier mounted on acam.

FIG. 13 is an end view of a canister carrier showing the canister cradlemounted with canisters and an end view of a ring gear.

FIG. 14 is a full side view of the canister carrier of FIG. 13.

FIG. 15 is a view in perspective of the canister carrier of FIG. 13.

FIG. 16 is a another embodiment of the stabilizer assembly of thisinvention using rubber wheels.

FIG. 17 is a full end view of a ring gear on this invention.

FIG. 18 is a full edge view of the ring gear of FIG. 17.

FIG. 19 is a view in perspective from the front, of the ring gear ofFIG. 17.

FIG. 20 is a full back view of a pinion gear on this invention.

FIG. 21 is a full side view of the pinion gear of FIG. 20.

FIG. 22 is a full view in perspective of the back of the pinion gear ofFIG. 20.

FIG. 23 is a top view of the secondary drive assembly mounted on theflat plate.

FIG. 24 is an end view of the drive assemblies of FIG. 23.

FIG. 25A is an illustration of the axis 1 orbital rotation of thecanisters when the apparatus is in motion.

FIG. 25B is an illustration of the axis 2 orbital rotation of thecanisters when the apparatus is in motion.

FIG. 25C is an illustration of the planar axis 2 translation and theplanar axis 1 translation of the canisters when the apparatus is inmotion.

FIG. 25D is an illustration of the planar axis 3 translation of thecanisters when the apparatus is in motion.

FIG. 26 is a full side view of one canister design of this invention.

FIG. 27 is partial enlarge view of the stabilizer assembly.

FIG. 28 is a full side view of a synchronous drive of this invention.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to FIG. 1, there is shown a full top view in perspective ofthe apparatus 1 of this invention. FIG. 2 is a full top view of theapparatus, FIG. 3 is a full front view of the apparatus, and FIG. 4 is afull end view of the apparatus of this invention from the end oppositeof the motor mounting. The Figures should be consulted for anunderstanding of the information that follows.

In FIGS. 1, 2, 3, and 4, there is shown a framework 2 for supporting theworking components of this invention and thus there is shown the legs 3of the framework 2, the upper bar frame 4, and a lower bar frame 5.

With reference to FIG. 5, there is shown a motor mount 6, mounted on thelower bar from 5, on which there is mounted a motor 7, also shown inFIG. 3 more clearly. The motor 7 is the main drive mechanism for theapparatus 1. The motor has a motor drive shaft 8, shown in FIG. 4, andattached to this drive shaft 8 is a driven flywheel 9.

As shown clearly in FIGS. 1, 2, and 3, the upper bar frame 4 has anon-stationary flat plate 10 surmounted on it which is supported atleast at each of the four corners 11, by shock absorbing mounts 12. Thenon-stationary fiat plate 10 has a front end 13 and a back end 14 (shownin FIG. 5). Rigidly mounted on the flat plate 10 are drive shaft mounts15, which hold the main drive shaft 16 which will be discussed in detailinfra. The drive shaft mounts 15 are located on either side of a smallopening discussed infra and on either side of the two larger openings18, also discussed infra.

The flat plate 10 has a centered small opening 17 and two largeropenings 18 on either side of the centered small opening 17. Located inthe two large openings 18 are processor assemblies 19, both processorassemblies being supported and driven by the main drive shaft 16, whichextends from the drive shaft mount 15 on one edge of the flat plate 10to the drive shaft mount 15 on the opposite edge of the flat plate 10.

There is centered on the main drive shaft 16, a main flywheel 20, whichmain flywheel 20 is essentially suspended by the main drive shaft 16 inthe small opening 17. Thus, the processor assemblies 19 consist of themain drive shaft 16 and the main flywheel 20.

Turning now to FIGS. 6 and 7, there is shown the details of the maindrive shaft 16. FIG. 6 is a full side view and FIG. 7 is a full view inperspective. The main drive shaft consists of a straight shaft 21 onwhich are mounted the main flywheel 20, centered between the ends 22 ofthe straight shaft 21, two cams 23 each spaced essentially equidistantbetween the main flywheel 20 and the ends 22 of the straight shaft 21.Also shown are the fasteners 23 for fastening the main drive shaft 16 inthe drive shaft mounts 15 (not shown in FIGS. 6 and 7). One preferreddrive mechanism for the main drive shaft is shown as a chain sprocket24.

The cams 23 are shown in detail in FIGS. 8, 3, 10, and 11. The camcomprises a solid cylinder 31, that has one flat end 32 and the oppositeend 33 configured at a slight angle θ from the vertical, said angle θcomprising less than about 15°. (FIG. 8 is a full side view of the cam23 of this invention). It should be noted that end 33 also has a slighthub associated with that end. In observing FIGS. 9 and 10, there isshown an opening 34, which is rectangular in configuration, throughwhich the straight shaft 21 of the main drive shaft 16 extends. Notefrom FIG. 11, that the opening 34 has an inset 35, and that theremainder of the opening 34 is angled through the cam 23. By this means,the straight shaft 21, when the main drive shaft 16 turns, causes thecanister carrier 26 attached to it to move in an irregular motion aswill be described in detail infra.

There is a canister carrier 26 mounted on each cam 23 (see FIGS. 12, 13,14, 15, and 16. The canister carrier 26 can carry one or more canisters27 as shown in FIGS. 13, 14, 15, and 16. As the cams 23 move, thecanister carriers 26 move. The canister carriers 26 have an outside hub28 (FIG. 12), wherein the outside hub 28 has an external surface mountedcradle 29. The outside hub 28 has an internal flat surface 37 supportingbearings 30.

The canisters can be fabricated from any material that will sustain theforces and not contaminate the material in the canister. Such useablematerials include, for example, stainless steel, plated steel,polycarbonate, aluminum and titanium, among others.

There is a mounted on the outside hub 28, a stabilizer assembly in oneembodiment, consisting of a pinion gear 36 FIGS. 20, 21, and 22, and aring gear 38, FIGS. 17, 18, and 19, and in another embodiment, astabilizer ring 39 and a stabilizer wheel 40 (See FIG. 16).

There is rotatably mounted on the main drive shaft 16, adjacent to thestabilizer ring gear 38 (or stabilizer ring 39 in the event of anotherembodiment), a stabilizer housing 42. The stabilizer housing 42 containsinternal bearings 43 adjacent to the main drive shaft 16. It should benoted that the pinion gear 36 surrounds the stabilizer housing 42 andfrom this position meshes with the ring gear 38. (See FIG. 12).

The ring gear 38 comprises an inward surface 44 and an outside surface45. The inward surface 44 is comprised of a plurality of gear teeth 46,the number and shape of gear teeth 46 being matched to mesh withcorresponding teeth on the adjacent pinion gear 36. It will be notedfrom FIGS. 17 and 19 that the gear teeth 46 slant forward within thering gear 28.

Turning now to FIGS. 20, 21, and 22, there is shown a pinion gear 36which operates in conjunction with the ring gear 38. Note that the teeth47 on the pinion gear 36 are configured to mesh with the gear teeth 46of the ring gear 38.

There is a stabilizer drive mechanism 48, best shown in FIGS. 2 and 23and 24, that is comprised of a secondary drive shaft 49 that issurmounted on the non-stationary flat plate 10, near the backend of theplate 10. The secondary drive shaft 49 is mounted in secondary driveshaft mounts 50, three of which are shown in FIG. 23, said mounts 50being mounted on the flat plate 10. The secondary drive shaft 49 has atleast three first drive wheels 51, one near each near end of thesecondary drive shaft 49 and one essentially centered on the secondarydrive shaft 49.

The main drive shaft 16 has at least three second drive wheels 52 beingaligned with the second end first drive wheels 51 on the secondary driveshaft 49. The centered first drive wheel 52 is aligned with a thirddrive wheel 54 mounted on a gear reducer 53 shown in FIG. 23. The gearreducer 53 is surmounted on the non-stationary fiat plate 10 between thedriven flywheel 9 and the secondary shaft 39. The gear reducer 53 has afourth drive wheel 55 mechanically connected to a third drive wheel 54by reducing gears (not shown). The fourth drive wheel 55 and centeredfirst drive wheel 52 being connected by a drive link 56 shown in FIG. 5.There is a second drive link 57 connecting each first drive wheel 51with an aligned second drive wheel 52.

FIG. 28 is a side view of the canister 58 mounted in the canistercarrier 26. This Figure shows an enlarged view of the mechanism forstabilization, namely, the cam 23, the bearings 30 on the cam, thestabilizer ring 38, the stabilizer hub 28, a drive link 57 which is abelt drive, the stabilizer bearing 43, and the main drive shaft 16.Canister sizes can ranged from 12 to 15 inches in length and from 4 to 8inches in diameter.

In this manner of linking the drive wheels, in operation, the main driveshaft 16 moves in a counter clockwise rotation and the secondary driveshaft 49 for the stabilizer units moves in a clock wise rotation. Due tothe gearing mechanism 53, the secondary drive shaft 49 moves much slowerthan the main drive shaft 16.

It is contemplated within the scope of this invention to substitute asynchronous drive unit for the secondary drive mechanism that drives thesecondary shaft.

FIG. 26 shown a full side view of one canister 27 design of thisinvention wherein there is shown the canister 27, the cap 60 and theatmosphere control valve 62.

Turning now to another embodiment of a stabilizer drive mechanism ofthis invention, there is shown in FIG. 28 a full side view of asynchronous drive 63 mounted on the non-stationary plate 10. Thesynchronous drive 63 is comprised of a belt system comprising a drivebelt 64 that is attached to a drive wheel 65 and linked to a secondwheel 66, which is mounted on the secondary shaft 49 (shown in FIG. 1).It should be noted from the arrows in FIG. 28 that the main drive shaft16 drives in a counter clockwise motion, and the secondary drive shaft49 drives in a clockwise motion.

The apparatus 1 is designed to impart forces in three planes and inorbital planes, one, two, or three, simultaneously (see FIGS. 25A to25D). FIG. 25A shows the axis 1 orbital rotation. FIGS. 25B shows theaxis 2 orbital rotation. FIG. 25C shows the planar axis 2 translation inthe vertical direction and the planar axis 1 translation in thehorizontal direction. FIG. 25D shows the planar axis 3 translation.

The apparatus acts on the media to translate it in all planessimultaneously. By doing so, the energy of the apparatus is convertedinto the stress state required to cause the exfoliation of theparticulate material. Other methods of milling, grinding, or sizereduction of particulates do not impart forces or translate the media inthese planes simultaneously. Most typically, these machines affect only2 or 3 planes, or e places and I orbital t most. The theory of thesemethods or machines is to move the media so that the media can do thework. This causes pulverization to occur. The operation of conventionalmachines does not create the correct stress environment to allowexfoliation to occur.

In addition to creating exfoliation via the shear forces, the presentinvention creates wear rate or deterioration on the media is minimizeddue to the machine doing the work and not the media. The apparatus ofthe instant invention moves the media so that the media and theapparatus act as one unit and are not disassociated.

The milling media is chosen so that it provides optimum mass andprovides correct shear forces. The mass is determined by the specificgravity of the media. If the specific gravity becomes too large, theforces that occur as the media comes into contact with the particulatematerial will exceed the shear thresholds and becomes tensile orcompressive in nature. Should the forces become tensile or compressive,pulverization occurs. If the specific gravity of the media becomes toosmall, the forces that occur as the media comes into contact with theparticulate material will offer limited effect.

The shear forces are determined by the inter facial surface energy ofthe media, if the interfacial surface energy with respect to thematerial being exfoliated becomes too large the forces that occur as themedia comes into contact with the particulate material will exceed theshear thresholds and become tensile or compressive in nature. Theperformance of the apparatus is optimized as the interfacial surfaceenergy and the surface area (achieved via diameter) is optimized. Mediaof mixed diameter may be used. If the surface energy between the mediaand material being exfoliated is too low, the media slips on the surfaceof the material and does not apply sufficient shear to causeexfoliation.

In order for the machine and the media to act as one unit and createexfoliation, the cavity and the amount of fill of media in the cavitymust be correct. The cavity must be filled in proportion to the lengthof movements created by the planar vectors. The performance of theapparatus is improved as the fill ratio, L_(overall) to L_(void) isoptimized.

In the method of this invention, wherein the apparatus 1 is used, it isnecessary to cause the shear forces (or energy) created, to be highenough in the basal plane that fracture (potential energy increase) willpredominately occur in those planes prior to fracture through tensileforces. Based on test results, the following best describes theconditions under which the apparatus should be operated.

The ratio of mass of media to mass of particulate should be in the rangeof 1:6 to 1:15; the height of media to height of canister should be 60to 90%; the free space to canister displacement should be less than 40%;the specific gravity of the media should be from 1.05 to 1.38. Preferredfor this apparatus and method is plastic media, although other knownexfoliating media can be used as long as it fits the parameters of usein this invention, namely, the media is chosen to match the specificsurface energy of the particulate. The actual operating time should bein the range of 45 minutes to about 1200 minutes.

The composition of matter that is a produced by this apparatus andmethod can be any particulate material, or any combination ofparticulate material. The preferred particulate material is one that hasbasal places end exfoliates to form platelets. Preferred particulatematter for this method is graphite exfoliated into graphenenanoplatelets. The particulate material is preferred to be high surfacearea graphene nanoplatelets comprising particles ranging in size from 1nanometer to 5 microns in lateral dimension and consisting of one to afew layers of graphene with a z-dimension ranging from 0.3 nanometers to10 nanometers and exhibiting very high BET surface areas ranging from200 to 1200 m²/g. In some embodiments partially exfoliated particulatematter with a BET surface area from 30 to 200 m²/g may be produced.

The apparatus may be capable of containing one or multiple containers.It may provide for more than one centroid of movement from one drivermotor.

1.-13. (canceled)
 14. A ring gear, said ring gear comprising: an insidesurface and an outside surface, said inside surface comprised of aplurality of gear teeth, the number and shape of gear teeth beingmatched to mesh with a corresponding gear on an adjacent pinion gear.15.-43. (canceled)